Hard (hot MgF2?) AR coatings on glass in Los Angeles?

Discussion in 'Optometry Archives' started by Guest, Aug 13, 2005.

  1. Guest

    Guest Guest

    I have just ordered a pair of uncoated glass eyeglasses. From what I can
    tell, it is very difficult or impossible to find a Los Angeles supplier of
    hot deposited quarter-wave magnesium fluoride coatings on glass. Does anyone
    have a suggestion along those lines? Does anyone have a suggestion for AR
    coatings of similar durability?

    Bill
     
    Guest, Aug 13, 2005
    #1
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  2. I don't know why it would be tough, since anyone who coats glass will
    use that technique on glass. Fairly common. Maybe the people you're
    talking to don't know what you're talking about. Try saying
    "anti-reflection coating". You will get the 1/4 wave MgFl coating...

    w.stacy, o.d.
     
    William Stacy, Aug 15, 2005
    #2
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  3. Guest

    cbf Guest

    I have tried to order computerglasses, but the glasses I received do
    not work.
    Do I need a special eye examination to determine the right focal
    length?
    What is normal focal length for computerglasses?
    I am nearsighted, how much do they have to add to my -2.75 and -3.25.

    Chris
     
    cbf, Aug 15, 2005
    #3
  4. Guest

    Guest Guest

    I am not a vision professional, but figuring out how to modify your distance
    prescription is neither rocket science or brain surgery.

    1. Measure the distance from your eye to where your monitor screen will be
    in meters.

    2. Take the reciprocal of that distance. That is 1/distance. That is the
    additional power in diopters required for your computer glasses.

    3. Get a prescription that is the same as you distance prescription except
    that number of diopters gets added algebraicly to your distance spherical
    diopter value.

    4. If you use bifocals, the add for bifocals is algebraicly reduced by the
    number of diopters you calculated above.

    That should be a simple calculation for optometrist or ophthalmologist to do
    and measure.

    Bill
     
    Guest, Aug 16, 2005
    #4
  5. Not so much a special eye exam, but during the exam the doc has to know
    what your desired working distance is, because there is no "normal focal
    length". In your case, the Rx below will be reduced by an appropriate
    amount based on that working distance and other factors such as the
    amount of your amplitude of accommodation and your near phoria
    (binocularity). It's not complicated, but it must be done correctly, or
    as you found out on the first try, don't bother...

    w.stacy, o.d.
     
    William Stacy, Aug 16, 2005
    #5
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